Reactivity of α-pinene epoxide in supercritical solvents

Thermal transformations of α-pinene epoxide in composite supercritical solvents that contain CO2, lower alcohols (ethanol, isopropyl alcohol) and water were studied in the temperature range of 387–575 K at pressure 13.5–21.5 MPa. Campholenic aldehyde and carveol were shown to be the main products of α-pinene epoxide reactions in supercritical solvents containing water. In the absence of water, thermolysis of α-pinene epoxide in supercritical solvent yields campholenic aldehyde and pinocamphone, with their total amount in the reaction mixture attaining 80%. Suggestions were made on the mechanism of α-pinene epoxide thermal isomerization depending on acidity of supercritical solvent.